Police joined forced with the RSPCA to take 55 dogs into care from suspected “puppy farms”.

Dozens of breeding bitches and puppies were seized after warrants were executed at six addresses in the early morning raids.

Six people - five men and one woman - were arrested a part of the joint operation between Durham Police and the animal welfare charity cracking down on puppy farming. A seventh person, a woman, was due to attend a police station voluntarily.

The suspects were taken police stations to be interviewed following the ‘intelligence-led’ operation in Shotton Colliery and Haswell.

It involved 70 police alongside 26 officers from the charity. RSPCA chief inspector Mark Gent said they had moved in after receiving a “large number of calls” about puppies sold in the area which had then died.

He added: “Forty three adult dogs, some of them breeding bitches, and 12 puppies, some of them very, very, young, have been seized are being checked by vets. Where there is evidence that animals are suffering we will take appropriate action against those responsible.”

Puppies seized included popular breeds such as Jack Russells, Chihuahuas and Jack Russell/Chihuahua crosses, known as ‘Jackhuahuas’.

New homes are not being sought as the inquiry continues.

Acting Inspector Jim Peel of Durham Police said the raids - part of Operation Sledgehammer, an ongoing campaign to disrupt organised crime - came after two months’ planning.

He went on: “Our concerns were not only for the welfare of the dogs but the welfare of buyers, who bought these animals in good faith only to discover they had underlying medical issues or missing documentation. This has caused financial problems for the unsuspecting buyers and in many cases personal distress.

“We have an ongoing commitment to tackle organised crime, which can come in many forms. And the resources we deployed today demonstrates how seriously we take this issue, which has been a major cause of public concern.”

RSPCA chief inspector Gent added: “There are two messages here, one to the breeders and very importantly one to members of the public. “There would not be this kind of business if it were not for people buying the puppies.

“Please, re-home a dog from an animal welfare organisation where possible.

“But if you must buy a puppy make sure you see the puppy with its mother, in the place where it has been living. Never, ever, arrange to meet the breeder in places like car parks.”

On Wednesday, the Mirror told how a schoolgirl was told her new puppy was an ‘illegal immigrant’. Little Milo had been with his new family just three weeks when trading standards came to take him away.